This disclosure relates to a high voltage igniter module used to ignite a lamp, for example a HID (High Intensity Discharge) lamp. Specifically, the disclosure relates to a mechanical design of a high voltage transformer and the associated igniter module.
Conventionally, high voltage igniter circuits are used to start HID lamps, such as an automotive lamp or headlight. The igniter circuit typically includes a lead frame or pc board and a transformer where the lead frame carries electrical components to produce a high voltage ignition signal. In addition, the lead frame may provide electrical connection points to power the ignition circuit and deliver the high voltage ignition signal to a HID lamp.
One example of a conventional embodiment of a high voltage igniter circuit includes a lamp receptacle mounted to an igniter circuit lead frame. The igniter circuit transformer is often mounted either directly to the lead frame or separate from the lead frame, and in the latter case, the transformer may be mounted to the lamp housing where the lead frame provides the necessary winding connection points.
High voltage igniter transformers produce the high voltage signals necessary to provide an ignition signal, and generally have a magnetic core, and primary and secondary windings surrounding the magnetic core. As is known, the output voltage associated with the secondary winding is related to the ratio of the number of secondary windings to the number of primary windings.
During the assembly of a HID lamp, it is common practice to pot the transformer with an insulating material to electrically insulate the windings from other electrical components contained within the lamp housing. In addition, potting of the transformer increases the overall stability of the transformer's performance. One drawback associated with potting of the transformer is the necessary step of characterization of the transformer subsequent to potting. Characterization includes testing of the transformer to determine the electrical specifications associated with the transformer.
Conventionally, the characterization of an igniter transformer occurs after the igniter module has been fully assembled. The igniter lead frame carries all electrical components associated with the igniter circuit, including the transformer. Subsequent to the assembly of the lead frame, the transformer is potted, and thus characterization of the transformer is performed with the transformer mounted and potted on the completed lead frame assembly. In the event the characterization of the potted igniter transformer is not within the required specifications, the entire lead frame is discarded or extensive rework is required to remove the potting material to replace the transformer.
Alternatively, the transformer is sometimes mounted within a lamp housing chamber separate from the lead frame, potted therein. The transformer is characterized subsequent to mounting and potting within the lamp housing. In the event the characterization of the igniter transformer is not within the required specification, the housing and transformer assembly are discarded or extensive rework is required to remove the potted transformer from the housing to replace the transformer.
This disclosure provides an igniter module and associated transformer to enable characterization of the transformer prior to the assembly of the transformer within the lamp housing or mounting of the transformer to an igniter lead frame. The disclosed igniter module eliminates the need to discard/rework a lead frame or housing as previously discussed if the characterization of an igniter transformer is determined to be out of specification subsequent to potting.
Other aspects of this disclosure relate to transformer potting apparatuses and methods. Furthermore, methods of winding a transformer core that is integrated with the transformer carriers are disclosed.